The present invention relates to a high-voltage transformer with liquid cooling, especially for use inside a subassembly composed of electromechanical components which have been assembled in a crowded arrangement, this transformer comprising a magnetic core with a winding, a cooling liquid surrounding this winding, a casing and insulated casing lead-throughs for external connecting lines.
Comparatively small, liquid-cooled transformers of this type are encountered exceptionally rarely, since the cooling-liquid expansion container, which is usually open, renders the transformer orientation-dependent, which excludes it from many possible applications. Moreover, the known oil-filled transformers are bulky, and are accordingly unsuitable for installation conditions involving extreme space limitations.
For these reasons, small high-voltage transformers for limited-space installation conditions, for example, for X-ray equipment, copiers, and the like are nowadays, almost without exception, potted in casting resin, and are air-cooled. Resin-potted transformers, however, are suitable only for very low power outputs, or when they are switched on for proportionately short periods. In order to be able to withstand the thermal expansions, the casting resins which are used must be adjusted in a manner whereby they are rendered soft. However, they become brittle within a comparatively short time, the consequence of this being that transformers which are under continuous load finally fail as a result of the breakdown of their insulations.